Fig 6. Forced activation of integrin αvβ3 leads to partial ECM fiber alignment.

A) Activation of the αvβ3 integrin can be achieved independent of Sdc1 by β3 clasp peptide. Integrin αvβ3 activities were accessed by measuring the attachment of HMF cells, including untreated HMF cells, HMF cells treated with 250μM control peptide (ctrl pep), HMF cells treated with 250μM β3 clasp peptide (β3 pep) and HMF mock cells treated with 2 mM MgCl₂, to culture dishes pre-coated with vitronectin after 15min incubation at 37°C. Columns labeled with different letters are significantly different (at least p<0.05). B) Representative confocal images of immunofluorescently labeled FN fibers of ECMs from HMF mock and Sdc1 cells treated with control or β3 clasp peptide. Original magnification: 200x. C) Mean fiber-to-fiber angles of the indicated HMF ECMs. Columns labeled with different letters are significantly different (at least p<0.05). Ctrl pep, control peptide; β3 pep, β3 clasp peptide.